Field of the Invention
Embodiments of the present invention generally relate to apparatus and methods for processing semiconductor substrates. More particularly, embodiments of the present invention relate to an apparatus and methods for heating a substrate in a chamber.
Description of the Related Art
The effectiveness of a substrate fabrication process is often measured by two related and important factors, which are device yield and the cost of ownership (CoO). These factors are important since they directly affect the cost to produce an electronic device and thus a device manufacturer's competitiveness in the market place. The CoO, while affected by a number of factors, is greatly affected by the system and chamber throughput, or simply the number of substrates per hour processed using a desired processing sequence.
During certain substrate processing sequences, such as, for example, chemical vapor deposition processes (CVD) or plasma enhanced chemical vapor deposition processes (PECVD), it may be desirable to pre-treat a substrate prior to performing a deposition process. In certain pre-treatment processes, the substrate may be heated, for example, using an anneal process, to a first temperature prior to the deposition process. During the deposition process, the substrate is heated to a second temperature different from the first temperature. For many deposition processes, the substrate is placed on a substrate support comprising a heater. This heater is used to heat the substrate to both the first temperature and the second temperature. When there is some variance between the first temperature and the second temperature, for example, when the second temperature is higher than the first temperature, there is a delay between the pre-treatment process and the deposition process so that the temperature of the heater may be increased from the first temperature to the second temperature. This delay leads to an overall increase in substrate processing time and a corresponding decrease in device yield.
Therefore, there is a need for an apparatus and process that can position and heat a substrate in a processing chamber in a cost-effective and accurate manner.